diff --git a/xpfe/AppCores/src/nsBaseAppCore.h b/xpfe/AppCores/src/nsBaseAppCore.h
index 1109e3013a36..635a74bc9f7b 100644
--- a/xpfe/AppCores/src/nsBaseAppCore.h
+++ b/xpfe/AppCores/src/nsBaseAppCore.h
@@ -41,7 +41,7 @@ class nsBaseAppCore : public nsIScriptObjectOwner, public nsIDOMBaseAppCore
   public:
 
     nsBaseAppCore();
-    ~nsBaseAppCore();
+    virtual ~nsBaseAppCore();
                  
 
     NS_DECL_ISUPPORTS